Manufacture of lead-covered electric conductors



(No Model.) v

' 1 J. FARRELL.

' MANEEAGTUEE 0E LEAD COVERED ELEGTVEIG coN-DUcToEs. 262,028. A PatentedAug. 1, 1282.

toJ

lings, making a part ot' this specication, in

Fig. 2 is a transverse sectional view ot' the r UNITED STATES PATENT GFFICE.

JOHN FARRELL, OF PITTSBURG, PENNSYLVANIA.

MANUFACTURE OF LEADiCO'VEREDVELECTRIC CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 262,028, dated August 1, 1882,

" l Appncauon nica January 26,1882. immonet.)

To all whom it may concern:

Be it known that I, JOHN FARRELL, a citizen of the United States, residing at Pitts-` burg, county of Allegheny, State of Pennsylvania, have invented' or discovered a new and `useful Improvement in the Manufacture of Lead-Covered Electric Conductors; and I do hereby declare the following to be a full, clear, concise, and exact description thereof, refer` ence being had. to the accompanying drawwhich-like letters indicating like partsy Figure l shows in sectional elevation parts of a lead-press for making electric conductors, the same being illustrative of my invention.

leadcylinder and wire-holder, taken in the plane ot' the line :c zr, Fig. 1. Figs. 3 and 5 lare perspective views to an enlarged scale of the lower end or point of different forms' of wire-holders adapted for use in accordance with my invention in making different forms oft-conductors; and Figs.4 and 6 illustrate in transverse section forms of conductors pro-V duced by means ofthe holders, Figs. 3 and 5, respectively.

My present invention relates to the manu' facture of lead-covered electric conductors or cables having two or more wires separately embedded in and covered by a body ot' lead;

and it consists in the construction ofthe wireholding mechanism and in certain combina- 1 tions of the same with a lead'cylinder and die and'means for supporting, adjusting, and operatin g the same, as hereinafter more fully described and claimed'.

In making compound y electric conductors having two or more wires for separate circuits l cure these results.

In the drawings, A represents the cylinder,

A' the pistouystem, and A2 the platen, ot' a .hydraulic press ofthe usual or any desired 5O` construction. The cylinder A is bound by two or more columns, A3, to an upper crosshead,

(not shown,) between which and the platen A2 to the upper cross-head/in any convenient way -in proper position to enter chambers b b as the cylinder is raised and force the lead charge therein downward. At their lower ends these chambers converge and form a common chamber, c, (see Fig. 2,) surrounding the lower end of the wire-holder E and opening or discharg; ing through a die, D, directly beneath such holder. This die has a central opening, d, whichmay be ot any desired form-as oval,

Around,augular, scalloped, dre-adapted to impart the desired exterior shape to the lead covering. The die is made adjustable vertically by means of sliding wedges r, seated in grooves or recesses r' in the upper end of block G and operated by screw-rods r2.

In order to prevent lead from entering the joint d' between cylinder B and block C, the upper face ot' die I) is raised above the plane of such joint and its side faces are fitted closely in the opening b' in the cylinder-bottom.

Vertically through the center of the cylinder is made a bore or passage, F', in which is screwed or otherwise secured a tubular bushing, F, its central opening, f, being ot' sufficient size to afford passage for the number ot' wires to be included in the cable or conductor, and also to hold a supply oi' wax, paraftiim, or other similar substance, as presen tl y described. The cylindrical part c3 of wire-holder E, Figs. l and 3, is slipped tightly into the lower end of bore F', with its upper end abutting against the bushing. lt is thus held rmly as against upward pressure of lead thereon. It may be sustained as against gravity by' friction or the tightness of its tit within the bore, leaving it free, however, totbe removed when desired for replacing with another of different form or size. The bushing F may also be removed for like reasons. Also, if preferred, the bushing and wire-holder may be connected or made integral ihsteadof separate. For economy and convenience in changing holders I prefer to make them separate, as shown. rIhe form ot the wire-holder at the point or lower end will depend upon the desired arrangement of wires in the conductor. I have shown two different forms, Figs. 3 and 5. in order to illustrate better different modes of applying niy invention. In Fig. 3 the wires are held in one plane, torming a tlat or oval conductor, as in Figli, a corresponding opening being made in die D to give the exterior form. The outer surface ot' this part ot the holder is also reduced or fiattened toward the point to a similar form, as at e2.

In order to afford a comparatively-unobstructed interior passage through the holder, so that the wires may be arranged compactly or brought into close relationship, I make such passage at the point in the form ot' an open slot, e, instead ot' providing separate perforations for each wire, as heretofore. Any desired numberof wires 'w may be passed through such slots close together or with very little space between them, the limit in this respect being only that which detracts from the successful working of the wires in different circuits. In order to afford the requisite strength at the point to resist the pressure ot'.lead, I provide one or more bridges or cross-bars, e', which brace the two walls and prevent compression or collapse.

In order to hold r the wires at proper intervals apart, and also to cause lead to ilow into the spaces between wires, I make grooves or depressions a in the outer surface ot' the wireholder, which are deepened toward the point and arranged on the two sides of wire-passage c, in pairs or directly opposite, and the wires fw are 'passed downward in lines between successive'pairs oi' such grooves, as illustrated in Fig. 3. As lead is forced downward past the holder its ilow will be directed by the surrounding die through such grooves into the spaces between wires. 'lhis tlow being once established with the wires in the position shown, they will be held in such relationship by the pressure of lead alone, and a solid body or covering ot' lead will be formed around each wire, as illustrated in Fig. 4. By raising or lowering the die D with relation to the point of the wire-holder such lead covering may bepressed upon the wires more or less tightly, as desired; or, on the other hand, the tubular passages occupied by the wires may be made larger than the wires.

Ordinarily I prefer to cover the wires with lead loosely, leavinga little space between the outer surface of the insulating-covering w and the surrounding lead wall, into which wax, parafne, asphaltum, or similar insulating and preservative substance may be forced. In order to effect this, the insulating material may be placed within the wire-holder and passage f, where it will he rendered liquid or plastic by heat from the lead in chambers b b, and in such conditionit may be forced by a down- Wardly-movin g plunger, by air-pressure or by other suitable means, through the open slots e into the space around each wire, thereby expelling air and moisture, perfecting the insulation ot' the wiresand preserving the fibrous or other covering w from decay, deterioration, orinjuries to which it may be subject in manufacture of or handling the conductor. I have included in the subject-matter of another application one method of introducing such material under air-pressure, consisting in sealing or closing the wire-openings in the delivery endof the conductor, whereupon a tendency is developed in the operation of applying the lead covering to form a vacuum at or a little below the point ot' the wire-holder, and pressure of air on the liquid or plastic material above forces it downward to supply such vacuum. Other means may be employed, however, for effecting this end, in all of which the open slots or passages e will facilitate the downward flow of such material by affording unobstructed open spaces between wires. The principal purpose, however, of the common or open wire-passages e is to permit of a close or compact arrangement ot' the'wires, so as to require a minimum quantity ot' lead for covering them. Where separate perforations for wire-passage are employed the walls which divide such perforations necessarily occupy considerable space. This is especially true where the point ot' the holderis made in the form of separate nipples. Such dividing Walls or nipples restrict the number ot wires that can be passed through a holder ot' given size. Byv leading the wires through common slotted openings e and spacing them by lead flow and pressure, as described, they can be brought closer together and less lead be employed in covering them than can be done with other forms ot' wire-holders ot' which I have knowledge.

By varying the depth of grooves a a greater or less amount ot' lead may be directed into the spaces between wires, so as to fill, or partially till, the same, whether the wires are arranged close together or separated by a considerable v space. Ordinarily, however, I prefer to make the grooves deep enough to ll such spaces with a solid body of lead, as in Fig. 4.

In Fig. 5 I have shown a form of wire-holder adapted to hold th'e wires in a circle for making a pipe-like conductor. (See Fig. 6.) In this form ot' holder the wires are passed downward through an annular passage, fi, between an outer shell, n, and inner body, n', bridges t" being employed in any desired number to give requisite strength. The wire-passage is thus made open and practically unobstructed, and the wires therein are spaced at its lower eX- tremity by the flow and pressure of lead, direction being given to such flow by grooves o o', made in the walls of the wire-passage, which grooves are arranged in pairs, the outer ones, o, being in the same radialv lines as the IOO IIO

IIS

' ward by the surrounding die.

-of the holder.

inner ones, o. t These grooves, with the open wire-passage fi, have the` same function and operation as before described with reference to Fig. 3. V

In illustrating this application of my invention I have also shown features of invention which are included in the subject-matter 0f another application-namely,a central supply of lead through the interior of the holder for forming the inner wall of the lead covering, the outer` wall being formed from a supply of lead forced downward around the exterior Such central supply, as illustrated in the present case, is taken from the main lead-chambers through passages h l1. to al1 inner chamber, H, within the circle of wires. From this chamber itis pressed downward by pressure within the main chambers past the cone-shaped core H', by which the iiow is directed outward to meet .that on the exterior from the main chambers, which is directed inlIn both this central and exterior supply the flow of lead will be directed by the grooves o o into the spaces between adjacent wires, thus spacing the wires and fillingmore or less between them with lead, depending upon the depth of grooves or depressions, substantially as before described. kIn this form of holder I prefer to make it and the bushing Fintegral, or rigidly connected, and screw them into the bore F', so as to secure stability as against pressure from the central lead-supply; Both forms of holders, Figs. 3 and 5, embody-the same principles of open wire-passages and spacing the wires by flow of lead. Various other forms may also be employed for making conductors of other shapes with other arrangements of wires which may employ the same principles of construction and operation.

' In order to hold the wires in proper relationship to the grooves in the holder before lead-pressure is applied, the ends of the wires may be drawn down through the die and united in any way at proper distance apart; also,

paper, cork, or other light packing may be placed in the slots or wire-passages e between wires to insure their separation and proper position, and also to prevent premature escape of the liquid contents of the holder. As lead covering is applied to the wires they will be drawn downward thereby and directed outward through side openings, c', in block C by any. suitable block, c2, placed below the opening. OrdinarilyT the paper or cork packing will be drawn down by the moving wires; but their v discharge will be insured when pressure is apsired length, a minimum quantityoflead be employed in covering the wires, and the wires be protected with any desired amount of preservative and insulating material surrounding each wire.

l claim herein as niyinvention- 1. A wire-holder for a lead-press, provided with an interior opening for passage of two or more wires, with open spaces between wires, and grooves or depressions in the side walls of such opening for directing a iiow ot lead into the spacesbetween wires, substantially as set forth. 1

2. In combination with the die of a leadpress, a wire-holder having an interior opening for passage of two ormore wires in common through the same tothe die, with open spaces between wires, and with grooves in the side walls of such opening for directing a ow of lead into the spaces between wires, substantially as set forth.

3. A wire-holder for a lead-press, having a common interior passage for two or more wires, with open space between wires, and grooves or depressions formed in the outer surface ofthe walls of such passage, arranged opposite each other in pairs corresponding in positionwith the spaces between wires, substantially as and for the purposes set forth.

4. The combination of lead-cylinder B, tubular support G, die D, resting on the support with its upper face raised above the lower surface of the cylinder, as described, and a Wireholder secured directly to the body of the cylinder above the die for passing wires to the die, substantially as set forth.

IOO

In testimony whereof' I have hereunto set i my hand.

JOHN FARRELL.

Witnesses:

R. H. WHiTTLEsEY, O. L. PARKER. 

